The present invention relates to an article of footwear having a removable insole.
In health-conscious circles and among working class people who must stand or walk a great deal, shoes with nubbed insoles are widely used and well-liked. Insoles are also known to have, in addition to the nub-type surface, magnetic metal parts at the four main points of the foot reflex zones. Shoes having such nubbed insoles are known to be available in open or half-open styles; however, in these styles the insole is typically joined solidly and undetachably to the sole of the shoe to prevent the insole from slipping about.
Non-removable nubbed insoles have been found to be undesirable because the space between the nubs tends to collect dirt, thus requiring the non-detachable insole (and hence the entire shoe) to be washed frequently. This care convenience, unfortunately, requires that the upper material of the shoe be made of a machine washable material, such as rubber or plastic, which is unappealing to many people.
Shoe structures with removable insoles have long been known in the art. However, the nubbed insoles with magnetic metal parts of which the present inventor is aware are solidly joined with the shoe sole. The reason for this is that such insoles have been used primarily in open or half-open shoe styles, and insoles simply laid in the shoe in the absence of a guide would inevitably slip about their entire border during walking. In an attempt to solve these problems, much effort has been expended in devising suitable methods of securing a removable insole to the sole.
German unexamined patent specification OS No. 28 45 880, for example, gives one proposed solution to this problem. It suggests connecting, in the heel zone, the insole to the sole using a burr closure material, such as that marketed under the tradename VELCRO. The problems associated with a poor connection of the insole, however, are not satisfactorily solved, since the forces created during walking also act upon the non-rigid front portion of the insole, causing the front portion of the insole to be displaced.